Photodetector Offers 1-A/W Responsivity

Tokyo-based Anritsu Corp. reports development of a photodetector with responsivity of 1 A/W, which it says improves optical-to-electrical signal conversion efficiency by up to 60 percent over conventional devices. The key to the performance improvement lies in the photodetector's use of an InGaAsP high-refractive-index layer and an InP low-refractive-index layer, with an InGaAs absorbing layer in between. Unlike the material structure of conventional photodetectors, the Anritsu system allows light traveling through the InP layer into the absorbing layer to be totally reflected and reabsorbed within it.